As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FUMES IN CABIN "DIRTY SOCK SMELL SHORTLY BEFORE LANDING, DURING TAXI AND AT THE GATE. MAINTENANCE: FOUND APU OIL LEAK FROM COMPRESSOR DRAIN CASE/FLUID INGESTION. REPLACED APU OIL COOLER AND APU OIL COLLING FAN (AALA202111020982) PER AMM 49-91-44. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.